Network based KVM switching system

ABSTRACT

A keyboard/video/mouse (KVM) switching protocol is disclosed in which KVM information is applied to a network of workstations. At least one data converter communicates on the workstation network and retrieves KVM information from the workstation network that is addressed to a server assigned to the converter. The converter places the KVM information in a format suitable to the assigned server and applies the converted KVM information to the appropriate standard device ports of the server. The system provides motherboard access to the servers that is characteristics of KVM switches but provides essentially unlimited scalability not known in traditional KVM switches.

This is a Continuation of: U.S. application Ser. No. 09/563,434 filedMay 3, 2000 now U.S. Pat. No. 6,681,250.

FIELD OF THE INVENTION

The invention relates to network switching systems and more particularlyto network switching of computer peripheral data.

BACKGROUND AND SUMMARY OF THE INVENTION

In years past, as corporate networks began to expand, there became agrowing need for so-called KVM switches to allow a single networkoperator to access and control multiple different computers with asingle keyboard, video, and mouse workstation. At first, KVM switchesprovided the maintenance operator with the ability to access between twoand eight different computers using a single keyboard, video and mouse.But, corporate networks grew in size, such that the size and complexityof KVM switches increased. Eventually, computer network operatorsdemanded KVM access between a workstation and thousands, and even tensof thousands, of different computers. The initial response was to scaleKVM switches such that a KVM switch that provided one workstation withaccess to 8 servers could instead be scaled to 8 additional KVMswitches, thus providing access to 8×8=64 computers. In this way, largernumbers of computers could be accessed via a single keyboard, video andmouse workstation.

Scaling remains a viable alternative in many computer environmentstoday. However, as the introduction of extremely vast numbers ofcomputers, such as in server farms and the like, become commonplace, theneed for a network operator to access many tens of thousands, orconceivably even many more computers becomes acute. Of course, KVMswitches can be scaled in increasing numbers in order to accommodate thegrowing numbers of computers that must be attached to a fewworkstations, but the increased number of scaled KVM switches becomes aspace consideration in large server farm areas.

Examples of the traditional KVM switches are shown in FIGS. 1 and 2. InFIG. 1, a traditional corporate network 10, such as a LAN, WAN,Internet, etc., provides a communication path for a number of servers11-13. The operation of the servers and the communication protocols usedby the network on the corporate network 10 are well known to theartisan. For purposes of brevity, they will not be repeated here. Theartisan will recognize, however, that many different protocols can beemployed for the servers 11-13 to communicate on the network 10 and thatmany protocols will be developed in the future to increase theefficiency of data travel on the network by the servers 11-13. Thepresent invention is not limited to any particular one.

In the KVM switch environment, as shown in FIG. 2, a number ofworkstations 17-19 communicate through a KVM switch 16 to servers A andB of the server set 14. The servers 14 communicate with each other andwith other servers, appliances, etc., over the corporate network 10.FIG. 2 illustrates the scalability of the KVM switches in that the KVMswitch 16 includes one output port connected to a second KVM switch 15.The second KVM switch 15 then connects to four additional servers C-F ofthe servers 14. Thus, if the KVM switch 16 provided only four outputport capability, the additional KVM switch 15 allows the users 17-19 tocommunicate with more than four servers (in this case of FIG. 2, sixservers 14).

The KVM switches 15 and 16 are known devices and are commerciallyavailable. Examples of these KVM switches are commercially marketed byCybex of Huntsville, Ala. as the Autoview family of products and the XPfamily of products. The KVM switches 15 and 16 provide a number offunctions in the embodiment of FIG. 2. First, when the servers 14 bootup, the KVM switches emulate keyboard, video and mouse initiationcommands such that each of the computers 14 believes that it is actuallyconnected to a single keyboard, video, and mouse workstation. The KVMswitches are programmed to emulate keyboard, video and mouse limitationcommands in accordance with one of any number of different KVMstandards, such as Sun, PS2, etc. for keyboard/mouse and VGA, SVGA, etc.for video. In addition, the KVM switches 15 and 16 poll the workstationsystem requirements (such as the type of mouse, type of monitor, andtype of keyboard) and provide data conversions that are necessary forotherwise inconsistent keyboard, video, and mouse devices to communicatewith the servers 14.

One of the earliest types of KVM switches known is described in U.S.Pat. No. 5,732,212, Perholtz et al. System and Method For RemoteMonitoring and Operation of Personal Computers. Perholtz describesremote KVM switching via the telephone network and local switching via adaisy-chain network of computers. Perholtz describes the use of a hostsystem communicating via the telephone network with a workstation togain motherboard access to a selected computer. In other words, Perholtzdiscloses that the remote user can reboot, cold boot, and perform otherfunctions that might otherwise require local motherboard access, whenthe remote user employs the host unit to gain the motherboard access.

The present invention provides a significant improvement overtraditional KVM switches and remote access KVM switches by providing KVMaccess—without traditional scaled KVM switches per se and without atraditional remote access unit—to any number of servers on a network,together with motherboard access to those servers. In traditionalnetwork access systems, the workstations and servers communicating viathe network exchange keyboard, video and mouse command data between oneanother, usually in the form of packeted information. Thus, intraditional systems like the commercially available PC Anywhere andother such remote systems, one can access a server via the telephonenetwork, the Internet, etc., and gain keyboard, video and mouse accessto the server. However, users of such traditional systems cannot gainaccess to the numbers of servers that may exist on, for example, acorporate LAN or Internet, while also gaining motherboard access tothose servers. In other words, in the past, the user could choosetraditional KVM switches that provided motherboard access but hadlimitations on practical scalability or could choose remote accessswitches which provided access to vast numbers of servers, but failed toprovide direct motherboard access.

The present invention solves both of the above problems by allowing anynumber of workstations to gain keyboard, video and mouse access to anynumber of servers on a corporate network, the Internet, or other networkin a relatively simplified structure. In accordance with the preferredembodiment of the present invention, a number of servers communicateover a corporate network, with the keyboard, video and mouse ports ofthe various servers connected via a cable to respective converter boxes.The converter boxes also communicate with a maintenance network, ontowhich the various user workstations also communicate. In accordance withthis embodiment, when a user of one of the workstations desires toaccess one of the servers, the user workstation communicates via themaintenance network to a corresponding converter for the desired serverto gain motherboard access to that desired server. The user can thenemploy the server to communicate with other servers via the corporatenetwork.

Although reference herein is made to converter “cores” and/or “units”one can appreciate that the converter described herein need not be a“box” or a “unit,” but can be a computer card, server card, or can beotherwise incorporated into any system component.

In the preferred embodiment of the present invention, any number ofusers can communicate on the maintenance network and any number ofservers can communicate on the corporate network such that any one ofthe users can communicate with any one of the servers and all of theservers can communicate one with another, without traditionally scaledKVM switches and without traditional KVM remote access devices, yetretaining full motherboard access. The preferred embodiment thusprovides essentially unlimited scalability while allowing each user togain motherboard access to any one of the associated servers.

In alternative embodiments, securities procedures are employed to limitmotherboard access to certain or all of the servers by certain or all ofthe workstations.

In other alternative embodiments, the corporate network and themaintenance network are not independent networks, but are a commonnetwork.

In still further embodiments, the converters are not independentlyassigned to each server, but service one or more servers.

In still alternative embodiments, the maintenance network and thecorporate network are bridged together.

BRIEF DESCRIPTION OF THE DRAWINGS

These, as well as other objects and advantages of this invention, willbe more completely understood and appreciated by careful study of thefollowing more detailed description of a presently preferred exemplaryembodiment of the invention taken in conjunction with the accompanyingdrawings, of which:

FIG. 1 is a schematic representation of a prior art corporate network;

FIG. 2 is a schematic representation of prior art KVM switches;

FIG. 3 is a schematic representation of a preferred embodiment of thepresent invention;

FIG. 4 is a schematic representation of the system of FIG. 3 withInternet and server management features;

FIG. 5 is a schematic representation of an example alternativeembodiment of the present invention;

FIG. 6 is a schematic block diagram of a KVM to LAN conversion card;

FIG. 7 is a schematic block diagram of an example server and converterin accordance with the present invention;

FIG. 8 is a schematic representation of an alternative example of thepresent invention;

FIG. 9 is a schematic representation of another example embodiment ofthe present invention; and

FIG. 10 is a schematic representation of an example converter inaccordance with the present invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIG. 3 illustrates a corporate LAN 10 onto which servers 11-13communicate with one another. The corporate LAN 10 is a typical LAN andthe servers 11-13 are common, over-the-counter servers, as depicted inthe prior art FIG. 1.

In accordance with the present invention, each server 11, 12 13communicates with a converter 21, 22, 23, which in turn communicatesover a maintenance network 20. User workstations 25, 26, and 27 alsocommunicate onto the maintenance network 20, including communicatingwith the converters 21, 22, and 23.

Although FIG. 3 illustrates 3 servers, 3 converters, 3 workstations, and2 networks, the present invention is not limited to a particularembodiment shown in FIG. 3 and may envision more or less of thecomponents shown. It is preferable to use separate converter units21-23, thus allowing servers 11-13 to be over-the-counter, unmodifiedservers. But, it is equally valuable to incorporate the converters 21-23into the servers 11-13, as for example, computer plug-in cards.

The converters 21, 22, and 23 act as intermediaries between the servers11-13 and the maintenance network 20. The intermediary converters 21-23thus allow the servers 11-13 to be typical, standard servers that can bepurchased over-the-counter, such as (but not limited to) any typical PC.The converters 21-23, in the preferred embodiment, are cable connectedto the servers 11-13 in a one-to-one correspondence. Converter 21, forexample, connects to server 11, converter 22 connects to server 12, andconverter 23 connects to server 13. In accordance with this embodimentof the present invention, each server on the corporate network 10 (whichmay exceed those shown in FIG. 3) has an associated converter (or atleast communicates with a shared converter) before communicating to themaintenance network 20.

In one embodiment, the converter 21 can take the form of a well-knownKVM switch, modified to convert KVM signals into a LAN protocol. Oneexample of such a switch is described in U.S. patent application Ser.No. 09/379,576 to Pinkston, which is incorporated herein by reference.Thus, the converter 21, for example, connects to the server 11 just as atraditional KVM switch would-connect to a PC in FIG. 2. That is, theconverter 21 connects via a hardwire cable to the keyboard, video, andmouse ports of the server 11 such that the converter 21 has directmotherboard access to the server 11 just as if the keyboard, video, andmouse used by the selected user workstation 25-27 were directlyconnected to the selected server. Between the converter 21 and themaintenance network 20 is a network card that allows the converter 21 toconvert signals received from the maintenance network 20 into thekeyboard, video, and mouse signals desired by the server 11. Similarly,the converter 21 takes keyboard, video, and mouse signals from theserver 11 and packets them (or otherwise formats them) into a dataprotocol acceptable for the maintenance network 20.

The user workstations 25-27 communicate with the various converters21-23 via the maintenance network 20. In the preferred embodiment, themaintenance network 20, as shown in FIG. 3, is an entirely differentnetwork than the corporate network 10. The maintenance network 20 mayoperate under the same protocol as the corporate network 10, but neednot do so. Thus, the maintenance network 20 and corporate network 10 mayeach follow Ethernet, LAN, ATM, wireless, CAT-5, TCP/IP protocols, orany other kind of data network connection or protocol that permitsdevices to communicate one with another.

When a user workstation, for example workstation 25, needs tocommunicate with a server, for example server 13, the workstation 25sends data onto the maintenance network 20 destined for the converter23. The converter 23 has an assigned device address on the network 20,just as would the workstation themselves. Most often, the data submittedfrom the workstation 25 to the converter 23 will be workstation inputsfrom the keyboard and mouse (or other input) devices of the workstation25 to be used to control the selected server 13. The workstation directsthe data to the converter 23 via standard network data addressingcommensurate with the address protocols dictated by the maintenancenetwork 20. The workstations 25-27 thus include network cards to linkthe workstation 25-27 to the maintenance network 20. The network cardsassist in the addressing of data onto the maintenance network 20 for thedesired converter 21-23. Once the workstation 25 sends keyboard andmouse data to the converter 23, the converter 23 takes the data from themaintenance network 20, converts it to a standard keyboard mouseprotocol in the format required by the server 13 and provides thosesignals to the respective keyboard and mouse ports of the server 13. Inthe end, the user workstation 25 has direct access to the server 13 justas if those keyboard and mouse devices of the workstation 25 weredirectly connected to the server 13.

In the opposite direction, in most cases, the converters will bepacketing sending digital video data from the server 13 to theworkstation monitor via the network 20.

Although described in the preceding paragraph in unidirectional fashion,communication between converter 23 and workstation 25 is bidirectional.Keyboard and mouse command data is sent, for example, from server 13 toconverter 23 to workstation 25 to set mouse sensitivity, keyboardlights, etc. Video commands are also sent, from time to time, from themonitor of workstation 25 back to the server 13 via the converter 23.

The converters 21-23 will perform all the necessary intermediary stepsrequired for any of the workstations 25-27 to communicate with any ofthe servers 11-13. That is, the converters 21-23 will respond duringboot-up to the servers 11-13 with the appropriate keyboard, video, andmouse initiation responses required by the server 11-13 in order tobluff the respective servers into believing that a proper keyboard,video, and mouse peripheral is connected thereto.

From a study of FIG. 3, one can see that any number of workstations25-27 (only limited by the number which can be maintained by maintenancenetwork 20) can communicate with any number of servers 11-13 such thatthe scalability of the KVM signal switching is not constrained by anyparticular physical requirements of a KVM switch.

It should be noted that the corporate network 10 is shown in FIG. 3 forillustrative purposes only and is not required by the present invention.In the modern environment, however, most servers 11-13 now communicatewith one another over a corporate network 10.

FIG. 4 illustrates the embodiment of FIG. 3 with added features,permitting the users 25-27 to communicate via the Internet 28. In theembodiment of FIG. 4, the maintenance network 20 has communicatingthereto a gateway/firewall 29, which connects the user workstations25-27 to the Internet 28. Of course, in some embodiments, the corporatenetwork 10 can be replaced by the Internet 28 such that the maintenancenetwork 20 communicates over the Internet 28, as do each of the servers11-13.

Also shown in FIG. 4 is a management server 30 communicating with themaintenance network 20 which allows a network manager to manage themaintenance network 20 and to communicate with each of the devicesattached to the maintenance network 20.

FIG. 5 illustrates an alternative embodiment to the embodiment shown inFIG. 3. In FIG. 5, the corporate network 10 provides a network backbonefor communication by a number of servers 31. In the embodiment of FIG.5, eight servers, server A-server H, are shown communicating with an 8×1converter 32. The 8×1 converter 32 communicates with the maintenancenetwork 20, which communicates with the workstations 25-27 (FIG. 3). Thedifference between FIG. 5 and FIG. 3 is that the converter 32 replaces anumber of independent converters 21-23 (for example, FIG. 3). When aworkstation 25-27 needs to communicate with any one of the servers 31,the workstation sends the appropriate addressing information to theservers, the 8×1 converter 32 picks up the data for all eight servers31, separates the data to the appropriate ports for each of the servers,server A-server H, and delivers respective KVM data to the appropriateserver destined for the appropriate server. Thus, in the embodiment ofFIG. 5, converter 32 not only retrieves KVM data from the maintenancenetwork 20 and converts it into KVM signal data for the KVM ports of aserver, it also sorts and delivers data received from the maintenancenetwork 20 to any one of the eight different servers. Of course, otherscalability factors (beyond 8×1) can be employed for converter 32.

The schematic structure of the server and converter will now bedescribed with respect to FIG. 7. In FIG. 7, the server 41 is shownincluding a motherboard 42, a network card 43, and a video card 44. Ofcourse, other server components will be included in the server 41, whichare not shown for purposes of brevity. The server 41 can be a standardPC with a network PCI card allowing the PC 41 to communicate via thenetwork 35. The network 35 can be a LAN or other network and can followthe Ethernet, IP/TCP or other data protocol, without restriction. As iswell-known, the server 41 will receive keyboard and mouse instructionsfrom a keyboard and mouse connected to its keyboard and mouse ports atthe motherboard 42 and can process those instructions using a processoron the motherboard to create appropriate data signals which are sentonto the network 35 via the network card 43. Further, the motherboard 42can respond to the keyboard and mouse signals via a video processor,which communicates video refresh signals from the video card 44 to avideo port. In the present invention, the converter 47 connects directlyto the video, keyboard and mouse ports of the server 41. In particular,the video port from the video card 44 of the server 41 connects into avideo port 45 of the converter 47. Similarly, keyboard and mouse portsof the server 41 (which connect directly to the motherboard 42), connectto keyboard and mouse ports 46 of the converter 47. If the converter 47is of the type shown in FIG. 5 (for multiple servers) then the converter47 will also include KVM ports 48 . . . 49 for n number of servers.

The converter 47 also communicates via a network card in the converter47 (not shown) to the maintenance network 20 via network connection 50.The maintenance network 20 can be a LAN, Ethernet, ATM, IP/TCP,wireless, CAT-5, etc. The connection 50 and converter 47 network cardwill correspond to whichever network protocol is employed for network20. Communicating with the maintenance network 20 is at least oneworkstation 51, and probably additional workstations (not shown).

As can be seen in FIG. 7, the converter 47 acts as an intermediarybetween the workstation 51, which communicates with the converter 47 viathe maintenance network 20, and the motherboard 42 of the server 41. Theconverter 47 can be the so-called “Keyview II” product commerciallyavailable from Cybex Computer Products of Huntsville, Ala., anddescribed in U.S. patent application Ser. No. 09/401,501 entitled“System and Method for Accessing and Operating Personal ComputersRemotely,” filed Sep. 22, 1999, the entire disclosure of which isincorporated herein by reference. Because the converter 47 connectsdirectly to the keyboard and mouse ports of the server 41, it hasmotherboard access to the motherboard 42 of the server 41. The converter47 thus can cause the motherboard 42 to perform cold boots and otherfunctions which can be accomplished only via direct motherboard access.Thus, the embodiment of FIG. 7 allows the workstation 51 to performfunctions at the motherboard 42 that the workstation 51 could notperform if it were simply connected to the network 35 and communicatingwith the motherboard 42 via the network card 43 and PCI bus of theserver 41.

Thus, the present invention differs substantially from traditionalremote access devices which communicate with a server via a servernetwork card, server modem, etc., since such traditional systems do notgain the direct motherboard access that the computer of the presentinvention gains through the keyboard and mouse server ports.

As can be seen in FIG. 7, the server 41 can be a standard,over-the-counter server with a standard motherboard 42, standard videocard 44 and standard keyboard and mouse ports. Further, the workstation51 can be any type of workstation, including workstation types that maynot be compatible with a selected server 41. Thus, by way of exampleonly, the workstation 51 can be a Sun-type workstation and the server 41can be a PC-server and the converter 47 will provide the necessaryconversions to allow the workstation 51 to communicate with the server41. The converters in the embodiment of FIG. 7 thus provide theconvenience of allowing users to employ over-the-counter workstations 51with over-the-counter computers 41.

Alternatively, the converter functions of the converter 47 can beincorporated into a server 41. That alternative embodiment, however,requires the server 41 to be customized to include the converter 47hardware and software. Thus, the present invention can be embodied inthe situation where the server is a standard over-the-counter serverwith an external converter 47, or where the server 41 is customized toinclude a converter card having the features of the converter 47providing direct motherboard access, or where the converter functionsare employed elsewhere in the server of the system.

The present invention is also different from prior art server cards 36(FIG. 6) which receive keyboard and mouse commands 39 and video commands40, and convert those commands into network packets for delivery onto anetwork 35. As shown in FIG. 6, some prior art systems accept keyboardand mouse data 39, packetize that data in a packetization function 37and deliver the packeted keyboard mouse commands onto a network 35. Suchserver cards 36 can also accept video 40 into a video-to-commandconversion unit 38 which converts the video signals into command types(such as draw a line from X Y coordinate to X1Y1 coordinate), whichcommands are packetized in packetization function 37 and delivered onthe network 35. In contrast, the present invention, an example of whichis shown in FIG. 7, takes digital video directly from the video port 47into the network port 50, to the monitor of the workstation 51 via themaintenance network 20, and provides direct motherboard access by theworkstation keyboard and mouse via the keyboard and mouse port 46 to themotherboard 42. Alternatively, the present invention can take digitalvideo directly from a video frame buffer of the server.

Further, with respect to converter 47, since the converter 47 receivesraw video at the video port 45, the converter 47 can convert videoresolutions of the server 41 to match the resolutions required by themonitor at the workstation 51. The converter 47 thus provides scalingand resolution conversions to the video 45 in addition to packetizationof the raw video data for transmission onto the maintenance network 20.

FIG. 10 illustrates an example converter in more detail. In FIG. 10, thevideo #1 signal and the K/M #1 signal from the video, keyboard and mouseports of a server enter the converter 100 at 101 and 102. The converter100 may optionally include a 1×N converter 110 (such as is describedwith respect to FIG. 5) such that KVM #2, KVM #3 . . . KVM #N signalscan communicate with X number of servers and provide those signals tothe network 20. The converter 100 receives the video signal from theserver (for example server 11 in FIG. 4) at video port 101 and providesit to video input circuitry 103. The video input circuitry 103 mayinclude amplifiers, conditioners, and other associated circuitry forvideo interfacing (as an alternative embodiment, the converter 100 canbe incorporated into server 11 and take video signals directly from theserver video frame buffer). The video input circuitry 103 provides theraw video data to a scaling resolution element 104. There, the raw videois scaled and resolved in accordance with the monitor used by theworkstation (25-27) that will receive the raw video data from thenetwork 20. The scaling and resolution circuitry 104 may be inaccordance with that described in U.S. Pat. No. 5,917,552, Video SignalInterface System Utilizing Deductive Control (Leone), commonly owned(which is incorporated herein by reference).

Next, the raw video is packeted at digital video packeting element 105.This digital packeting can be performed in accordance with U.S. patentSer. No. 08/909,924 by O'Dryna et al., (filed Aug. 12, 1997) and U.S.patent Ser. No. 09/100,582 by O'Dryna et al. (filed Jun. 19, 1998), bothcommonly owned, both of which are incorporated herein by reference.

The keyboard and mouse signals come through on the K/M #1 line toconverter port 102. As described previously, the keyboard and mouseconnections provide direct access to the motherboard of the server. Thekeyboard and mouse port 102 connects to the keyboard mouse I/O 108 whichcondition signals to and from the server 11 keyboard and mouse ports.The keyboard and mouse signals then proceed to the keyboard mouseconversion element 107 where appropriate conversions are performed toensure that the keyboard and mouse signals from the workstation and theserver are consistent in format. Keyboard and mouse signals are packetedin element 106.

The converter 100 also includes elements communicating with the videoI/O 103 and keyboard and mouse I/O 108 to answer command instructionsprovided by the server, for example at server boot-up. Theseinstructions could include for example mouse protocols, keyboardstandards, and monitor resolutions, etc.

Once the raw digital video is packeted at element 105 and the keyboardmouse signals are packeted at element 106, they are provided to thenetwork card 109, which sends the packets onto the network 20, addressedto the appropriate workstation 25-27, etc.

Some elements of converter 100 have been omitted from FIG. 10 forpurposes of brevity, but one can recognize that converter 100, to theextent not specifically shown in FIG. 10, otherwise operates inaccordance with traditional KVM switches, such as are commercialized byCybex as Autoview and xP series switches.

FIG. 8 illustrates an alternative embodiment of the present invention inwhich the corporate network 10 and maintenance network 20 have beencombined into a single network 80. As can be seen in FIG. 8, theworkstations 87 and 88 communicate with the network 80, as do servers81, 83, and 85, to which the workstations may gain KVM control. When theservers 81, 83 and 85 communicate with each other over the network 80,they do so by addressing each other directly over the network 80.Workstations 87 and 88 can also communicate with the servers directly byaddressing data to the server themselves. When, however, theworkstations 87 and 88 need further control over the servers 81, theworkstations address the converters 82, 84 and 86 and the converters inturn transfer the keyboard, video, and mouse information to theassociated server directly to the motherboards 89, 90, and 91.

Thus, in FIG. 8, if workstation 87 needs to control server 83, theworkstation 87 would address the converter 84 at IP address D by sendingkeyboard, video and mouse information from its own IP address G to theIP address D of converter 84. The embodiment of FIG. 8 assumes anInternet protocol type data structure on the network 81, but of courseother data protocols may be substituted therefore. Once the workstation87 sends KVM data to the converter 84, the converter 84, which hashardwire connection to the motherboard 90 of server 83 via the keyboardand mouse ports of the server 83, provides the keyboard and mouseinformation to the motherboard 90 and the video information to the videocard of the server 83 (not shown).

A still further embodiment of the present invention is shown in FIG. 9in which network 10 and maintenance network 20 have associated servers93 and 94 with associated converters 95 and 96 communicatingtherebetween. Workstation 97 communicates on maintenance network 20 andcontrols servers 93 and 94 via the converters 95 and 96, as described indetail above. In the embodiment of FIG. 9, however, bridge 92 connectsnetwork 10 and maintenance network 20, thus effectively tying network 10and network 20 into a common network structure. In FIG. 9, themaintenance network 20 remains independent of the network 10 and yet theworkstation 97 can still access server 93 and server 94 directly viabridge 92. The embodiment of FIG. 9 also provides the advantage ofallowing the workstation 97 to get direct motherboard access to theservers 93 and 94 via converters 95 and 96, without employing the bridge92.

While the invention has been particularly shown and described withreference to embodiments thereof, those skilled in the art willunderstand that the foregoing and other changes in form and detail maybe made therein without departing from the spirit and scope of thepresent invention.

1. A converter for communicating workstation and video data between (1)a workstation having an associated unique workstation Internet Protocol(IP) address and a workstation network port communicating with a commonIP network using the unique workstation IP address and (2) one server ofa plurality of servers, each server having its own unique server IPaddress and unique server network port providing communication with eachother server across the common IP network, the converter for the oneserver comprising: a network interface facility having an associatedunique converter IP address and a converter IP network portcommunicatively coupling the converter via the unique converter IPaddress to the common IP network and thereby to the workstation networkport via the unique workstation IP address, the network interfacefacility receiving the workstation data from the workstation via thecommon IP network in a packet-switched format; a conversion facility toaccept the workstation data from the workstation in the packet-switchedformat and to convert the workstation data to a native server format; acommunication channel isolated from the common IP network andcommunicatively coupling the converter to the one server, saidcommunication channel coupling the workstation data in the native serverformat between the converter and an input port of the server off of thecommon IP network, wherein: the conversion facility further to acceptthe video data from the server via the communication channel in a nativevideo format and converting the video data to a packet-switched format;the network interface facility further receiving the video data in thepacket-switched format from the conversion facility and transmitting thevideo data in the racket-switched format to the workstation via thecommon IP network using the unique workstation IP address.
 2. Theconverter of claim 1, wherein the workstation data is keyboard data orcursor control data.
 3. The converter of claim 1, wherein the nativeserver format is a server keyboard or mouse format.
 4. A method ofcommunicating data between a workstation and one server of a pluralityof servers, the plurality of servers communicating with each other andthe workstation across a server network, the method comprising:transmitting the data from a first network address as packeted keyboardor cursor control data from the workstation across the server networkwith a designated second network address as a destination; receiving thekeyboard or cursor control data from the packet switched network at adevice other than the server, the device being associated with thesecond network address; connecting the device associated with the secondnetwork address to the one server via a channel independent of theserver network, the one server having an associated third networkaddress; the first, second and third network addresses being unique toeach other; converting the keyboard or cursor control data into a formatsuitable for transmission to a keyboard port or a cursor control port ofthe server; transmitting the keyboard or cursor control data into thekeyboard port or cursor control port of the server via the channelindependent of the server network; receiving video data from a videoport of the server at the device via the channel independent of theserver network; transmitting the video data from the second networkaddress as packeted video data across the server network with the firstnetwork address as a designated destination; and receiving the videodata from the packet switched network at the workstation associated withthe first network address.
 5. The method of claim 4, wherein the servernetwork is an Internet Protocol network.
 6. The method according toclaim 4 wherein the device is physically co-located with the server. 7.The method of claim 4, wherein the native server format is a serverkeyboard and mouse format.